EP0001043B1 - Synthesis and aqueous recovery of hydroquinone - Google Patents

Synthesis and aqueous recovery of hydroquinone Download PDF

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Publication number
EP0001043B1
EP0001043B1 EP78100526A EP78100526A EP0001043B1 EP 0001043 B1 EP0001043 B1 EP 0001043B1 EP 78100526 A EP78100526 A EP 78100526A EP 78100526 A EP78100526 A EP 78100526A EP 0001043 B1 EP0001043 B1 EP 0001043B1
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EP
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Prior art keywords
hydroquinone
phase
aqueous
distillation
acetone
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP78100526A
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German (de)
English (en)
French (fr)
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EP0001043A3 (en
EP0001043A2 (en
Inventor
William Shepherd Hollingshead
Edward Norbert Nowak
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Goodyear Tire and Rubber Co
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Goodyear Tire and Rubber Co
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Publication of EP0001043A2 publication Critical patent/EP0001043A2/en
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
    • C07C37/08—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by decomposition of hydroperoxides, e.g. cumene hydroperoxide
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/685—Processes comprising at least two steps in series
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
    • C07C37/72—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by liquid-liquid treatment
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
    • C07C37/84—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by crystallisation

Definitions

  • the field of this invention is the synthesis of hydroquinone by acid cleavage (Hock-splitting) and recovery of hydroquinone from the reactor effluent.
  • hydroquinone must be a white crystal or crystalline powder which meets ASA specification PH 4.126-1962 in order to be photographic grade. A high standard for whiteness is imperative for photographic grade material. Hydroquinone is used widely as the main ingredient in black and white film print developing.
  • Hydroquinone is also useful as a polymerization inhibitor and 2 s an antioxidant. Hydroquinone itself and derivatives, such as 2,5-di-tert.-butylhydroquinone and butylated hydroxyanisole (BHA), are used for the prevention of oxidation in animal fat and aviation fuels.
  • BHA butylated hydroxyanisole
  • tars By-products of the Hock-splitting (or rearrangement) reaction, referred to as tars, are believed to be the major impediment to high purity.
  • these tars are: p-isopropylphenol, a-hydroxy-p-isopropylphenol, p-diisopropylbenzene, p-isopropenyl- phenol, isopropenyl acetophenone, and dimers and trimers of the product and by-products.
  • These impurities and by-products must be removed from the rearrangement product mixture in order to obtain a good color grade and high purity product.
  • Benzene has been the subject of recent regulatory action.
  • U.S. Occupational Safety and Health Administration has recently promulgated an emergency temporary standard bringing the average allowed exposure of a worker to benzene down to one part per million on a time- weighted basis, and allowing no more than five parts per million (ppm) peak exposure in factories during any 15-minute period. Even prior to this regulation the exposure was limited to 10 ppm. Thus, it is desirable to limit as much as possible the use of benzene in the process for making hydroquinone.
  • MIBK methyl isobutyl ketone
  • Reactor effluent is subjected to neutralization, distillation to remove the acetone formed in the reaction and part of the MIBK reaction solvent, extraction of the distillation bottoms with water, extraction of the hydroquinone-bearing aqueous extract with MIBK to remove impurities, concentration of the purified aqueous extract, and crystallization of the hydroquinone.
  • Parts of this process are described in German Offen- legungsschrift 2446992, April 15, 1976.
  • a process for purifying hydroquinone by successive aqueous extractions of the tars is described in U.S. Patent 3,900,523. In that process it is a steam distillation following the rearrangement reaction which removes the reaction solvent and forms a crude hydroquinone aqueous solution consisting essentially of water, hydroquinone, solvent and tar substances.
  • the concentration of hydroquinone in this aqueous solution must be about 23 weight percent or more at a temperature of about 60°C.
  • a process combining the steps of rearrangement in an MIBK solvent followed by distillation and extraction steps to remove tars and recrystallization of the hydroquinone from acetone has great promise because it eliminates the use of benzene and other hazardous organic liquids as both a solvent and extractant and results in a product of very high purity.
  • One drawback to such a process is the great number of unit operations which must be performed. This invention combines the desirable features of the process just described and, in addition, reduces the number of steps required.
  • Hydroquinone may be synthesized by the improved process comprising the steps of:
  • the acid catalyst may be present in the range from .05 to 3.0 weight percent of the reaction mixture. Water adversely affects the reaction by reducing acid strength and must be below 3 weight percent, prefera ly below one weight percent.
  • the preferred temperature of the reaction is from 65°C to 85°C.
  • the reaction solvent may be any water- insoluble liquid suitable for the selective extraction process (described in the Background section) for isolating p-diisopropylbenzene dihydroperoxide.
  • the extract from the dehydroperoxide process is the feed to the hydroquinone synthesis process.
  • suitable solvents are: methyl isopropyl ketone, diisopropyl ketone, methyl isobutyl ketone, cyclohexanone, 1-pentanol, 3-pentanol, diethyl ether, diisopropyl ether, ethyl isopropl ether, and mixtures of the foregoing with acetone.
  • the pH of the reaction effluent is adjusted to from about 2.5 to 5.5, preferably within the range of 3 to 4.
  • Anhydrous ammonia is particularly effective as a neutralization agent because it is readily dispersible in the organic solution.
  • Other bases which are useful are described in U.S. Patent 3,927,124, column 2, lines 67-68 and column 3, lines 1-9, which is incorporated by reference into this application. That same patent describes a process for the pH adjustment or neutralization at columns 3, lines 15-54 which is also incorporated by reference into this application.
  • the pH adjustment may also be accomplished by simply mixing the base with the rearranger effluent.
  • the salt of the acid catalyst formed during the neutralization or pH adjustment step is insoluble in the reaction solvent and may thus be removed by precipitation, filtration or any other suitable solid liquid separation step. If precipitation is used, water is added to the reactor effluent prior to the salt separation step to facilitate the separation by dissolution of said salts into an aqueous phase which is withdrawn.
  • the supernatant liquid or fiitrate from the salt separation step flow on to a distillation column in which are combined the unit operations of distillation to remove the acetone and reaction solvent and extraction of the hydroquinone into a water phase.
  • the hydroquinone content of this supernatant stream will generally be from 1 to 15 weight percent, and is preferably from about 5 to 15 weight percent.
  • the distillation column feed includes two other streams, an acetone stream and an aqueous stream, both of which may contain impurities and minor constituents not critical to the present process.
  • the amount of water fed to the distillation column should be sufficient to both insure the transfer of most of the hydroquinone to the aqueous phase and to compensate for water lost in the overhead with any reaction solvent/water azeotrope.
  • the ratio of organic to aqueous phase in the distillation bottoms is critical and depends on how pure the p-diisopropylbenzene dihydroperoxide feed is. The purer the feed is the smaller may be the ratio because the organic phase would have to "hold" less tars. Generally the weight ratio is between 0.5:10 and 5:10 and preferably is about 1:10. A ratio of 1:10 gives a good balance between the goals of minimizing the flow of organic phase in the bottoms and allowing some flexibility in the operation of the distillation column. In experiments an organic to aqueous phase volume ratio of about 1/10 in the distillation towers bottoms resulted in the transfer of 88 weight percent of the hydroquinone to the aqueous phase. The solubility of tars in water is negligible.
  • the acetone feed along with the acetone obtained as a product of the rearrangement reaction is removed by distillation as overhead.
  • the overhead also includes most of the reaction solvent (e.g. MIBK).
  • MIBK reaction solvent
  • the tower bottoms stream comprises an organic phase comprising reaction solvent in which are dissolved the tars and some hydroquinone and a water phase in which is dissolved most of the hydroquinone.
  • concentration of hydroquinone in this aqueous phase is about 5 to 25 weight percent, preferably 8 to 10 weight percent.
  • the concentration step (F) is generally run at a temperature from 65° to 100°C., preferably from 65° to 75°C.
  • the aqueous phase is usually concentrated to from 25 to 30 weight percent hydroquinone. Lower concentrations tend to reduce crystallization yields, and higher concentrations tend to give a slurry which is too viscous.
  • the term "repulping” as used herein means dissolving a wet precipitate such as a filter cake or centrifuge cake in a solvent.
  • concentration of hydroquinone in the mixture leaving step (I) is generally between 30 and 50 weight percent. The purer the cake is, the higher the concentration can be.
  • step (M) The conditions necessary for step (M) are a volume flow of water extractant that is several times that of the organic feed (e.g. 7:1) and an extraction temperature of about 80°C. Temperatures of up to 120°C are permissible if pressure is employed in the extraction.
  • the function of the solvent recovery step (0) is to purify the tar-containing raffinate from step (M) so that it may be recycled back into the process. This purification may be done by any suitable unit operation such as distillation or evaporation.
  • step (F) the water evaporated in concentration step (F) is utilized as an extractant in step (M) and is recycled to step (D) thus greatly reducing the water consumption which would otherwise be necessary.
  • the single figure is a diagrammatic representation of the process of the present invention.
  • the overall process will be described with reference to the flow diagram, with the proviso that this diagram is an exemplary embodiment of the invention and the process is not limited to this particular arrangement.
  • the solid liquid separation step (H) is shown as a centrifuge; however, this operation could be done by a filter.
  • the symbols represent unit operations, and ancillary equipment such as heat exchangers, pumps, and steam jet ejectors have not been illustrated.
  • secondary process streams e.g. vapor leaving crystallizers
  • utility streams e.g. steam
  • the rearranger feed 1 contains p-diisopropylbenzene dihydroperoxide, reaction solvent and minor amounts of unreated p-diisopropylbenze (precursor to the dihydroperoxide) and impurities such as diisopropylbenzene monohydroperoxide and ⁇ -hydroxy-a'-hydroperoxy diisopropylbenzene.
  • This feed is mixed in the rearranger reactor 3 with the acid catalyst 2 (such as sulfuric acid).
  • the acid catalyst 2 such as sulfuric acid.
  • Typical conditions for the rearrangement reaction are 82°C. and 0-138 kilopascals.
  • the rearranger effluent 4 is mixed in-line with anhydrous ammonia gas which enters via stream 5 and water which enters via stream 6.
  • the acid present in the reactor effluent is neutralized and this neutralized stream 7 enters the salt separator 8.
  • the salt separator 8 consists of a vessel designed so that it has sufficient holding capacity to permit the transfer of the acid salts to the aqueous phase 9 and the removal of the supernatant organic stream 10 without disturbing this transfer.
  • Stream 10 is mixed with the acetone filtrate 107 from centrifuge 106 and the combined stream 11 flows onto the distillation column 20.
  • an aqueous stream 12 which consists of a combination of the aqueous extract 48 from extraction column 47 and filtrate stream 75 from centrifige 70. Any deficiency in the amount of water necessary is made up by adding water via stream 22.
  • the distillation is carried out, as described in the summary section, so as to remove all of the acetone and most of the reaction solvent in the distillate 25.
  • the hydroquinone is extracted into the aqueous phase and tars are concentrated in the organic phase in the distillation bottoms 28.
  • phase separator 30 is a vessel designed to permit the decantation of the organic phase from the aqueous phase which contains the hydroquinone.
  • the aqueous phase 32 is withdrawn and transferred to concentrator 40.
  • the concentrator 40 is typically operated under a vacuum (71.982 kPa) and at an elevated temperature (e.g. 66°C.).
  • the function of the concentrator is to remove sufficient water in order to successfully carry out the next unit operation, crystallization.
  • the water removed leaves the concentrator via stream 41.
  • the concentrate exits the concentrator via stream 45.
  • crystals of hydroquinone are formed through gentle cooling and agitation, forming an aqueous slurry.
  • This slurry 65 may be removed on a continuous or batchwise basis from the crystallizer.
  • Stream 65 flows on to centrifuge 70 in which the wet hydroquinone crystals 77 are separated from the aqueous filtrate 75.
  • the wet crystals 77 are transferred to repulper 80.
  • the repulper 80 is an agitated vessel in which the wet hydroquinone crystals are dissolved in acetone which enters via stream 78.
  • the mixture of hydroquinone, acetone and water thus formed, 85 flows from the repulper to crystallizer 90.
  • Crystallizer 90 performs a similar function to crystallizer 60 with the exception that the solvent system is principally acetone instead of water. A slurry of hydroquinone crystals in the acetone solvent 95 exits the crystallizer 90 and flows on to centrifuge 106.
  • Centrifuge 106 separates the hydroquinone crystals 110 (this time wet with acetone) from the acetone filtrate 107 which is recycled to the distillation column 20. Following centrifugation, the wet hydroquinone crystals are conveyed to a drier for conventional handling thereafter.
  • the tar-containing organic phase 35 is transferred from phase separator 30 to extraction column 47 where it is contacted countercurrently with aqueous stream 44 (recycled stream 41 condensed in heat exchanger 43).
  • Extraction column 47 is operated, as stated in the summary section, so that most of the hydroquinone in the organic phase is extracted into the aqueous phase.
  • the hydroquinone-containing aqueous extract 48 is recycled to distillation column 20.
  • the tar-containing organic raffinate 49 flows on to solvent recovery unit 51 where it is separated into relatively pure reaction solvent 54 and concentrated tars 52.
  • a feed mixture was made by combining 230 grams of p-diisopropylbenzene dihydroperoxide (p-DHP) cake with 615 grams of MIBK and 93 grams of acetone and warming to 60°C.
  • the cake was obtained as the product of a process similar to that described in U. S. Patent .3,883,600 (column 7, lines 9-13 and in Chemical Engineering, June 9, 1975, pp. 50-51 (vacuum drum filter cake).
  • the cake was comprised of 85.6 percent p-DHP, 12.8 percent ⁇ -hydroxy-a'-hydroperoxy diisopropylbenzene and 1.6 'percent p-diisopropylbenzene.
  • the rearrangement was initiated by the addition of this p-DHP feed to a nitrogen-purged three liter flask containing 2 grams of concentrated H 2 SO 4 in 80 grams of acetone. An additional one gram of concentrated H 2 so 4 was added to the reaction flask after one-half of the p-DHP feed had been added.
  • the temperature of the rearrangement was maintained at 65 to 75°C. and was controlled by the adjustment of the rate of the addition of the feed and with external cooling in an ice bath. After all the feed was added, the rearranged solution was allowed to stand with stirring for an additional 10 minutes, neutralized with anhydrous NH 3 to a pH of 3.5 to 4.5 and vacuum filtered to remove the salts.
  • the aqueous layer from the phase separation of the distillation tower bottoms was then concentrated by vacuum distillation to a hydroquinone content of 25 percent, cooled to 25°C. and centrifuged to obtain a wet hydroquinone cake (stream 77).
  • the centrifuge filtrate (stream 75) was recycled to the distillation tower.
  • the hydroquinone cake which contained about 20 percent water, was combined with an amount of acetone equal in weight to the cake, warmed until in solution, cooled to 20°C., and centrifuged to recover high purity hydroquinone.
  • the centrifuge filtrate (stream 107) was recycled back to the distillation tower.
  • Color number is an arbitrary color measurement obtained by comparing a 5 percent hydroquinone solution in a dilute acetic acid with a known set of color standards.
  • the color standard is a platinum/cobalt (Pt/Co) standard of the American Public Health Association (APHA).
  • Pt/Co platinum/cobalt
  • a standard color number curve is plotted in using various solutions of the standard. As furnished, the standard has a color number of 500. A one percent solution would then have a color number of 5, etc.
  • Measurements of light absorbance are made of an instrument such as a Beckman Spectrophotometer at a wave length of 390. For hydroquinone, a color number of less than or equal to 20 corresponds to commercially available photograde hydroquinone and meets the ASA specification for color and acetone solubility.
  • the procedure described in the experimental section above was worked batchwise through seven cycles to determine the extent of color build-up or the decay of purity of hydroquinone.
  • the product of the seventh cycle had a purity of 99 percent and a Pt/Co color number of 22.
  • the crude cake before crystallization from acetone had a Pt/Co color number of about 300 and had a needle-like structure with rather poor flow properties characteristic of hydroquinone recovered by crystallization from water.
  • the solvent recovery step (0) represented by item 51 on the flow diagram, may be eliminated if the organic raffinate (49) can be utilized or properly disposed of.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
EP78100526A 1977-09-14 1978-07-27 Synthesis and aqueous recovery of hydroquinone Expired EP0001043B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US05/833,204 US4119791A (en) 1977-09-14 1977-09-14 Aqueous recovery of hydroquinone
US833204 1986-02-25

Publications (3)

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EP0001043A2 EP0001043A2 (en) 1979-03-21
EP0001043A3 EP0001043A3 (en) 1979-04-04
EP0001043B1 true EP0001043B1 (en) 1981-10-14

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EP78100526A Expired EP0001043B1 (en) 1977-09-14 1978-07-27 Synthesis and aqueous recovery of hydroquinone

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US (1) US4119791A (enrdf_load_stackoverflow)
EP (1) EP0001043B1 (enrdf_load_stackoverflow)
JP (1) JPS5452041A (enrdf_load_stackoverflow)
BR (1) BR7805951A (enrdf_load_stackoverflow)
CA (1) CA1103277A (enrdf_load_stackoverflow)
DE (1) DE2861158D1 (enrdf_load_stackoverflow)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3037476A1 (de) * 1979-10-09 1981-04-23 Sumitomo Chemical Co., Ltd., Osaka Verfahren zur trennung von resorcin und hydrochinon voneinander bzw. zur abtrennung und reinigung von hydrochinon aus verunreinigtem rohhydrochinon
EP0085289A1 (en) * 1981-12-24 1983-08-10 Monsanto Company Process for direct neutralization of product mixture resulting from acid catalyzed cleavage of alkyl aromatic hydroperoxides
US4463198A (en) * 1982-08-23 1984-07-31 The Goodyear Tire & Rubber Company Method for the rearrangement of dialkylbenzene dihydroperoxides to dihydric phenols
DE69318007T2 (de) * 1992-11-05 1998-09-17 Mitsui Petrochemical Ind Verfahren zur herstellung von aromatischen hydroxyderivaten
JP4473395B2 (ja) * 2000-02-18 2010-06-02 住友化学株式会社 ヒドロキシ芳香族化合物の製造方法
FR2903100B1 (fr) * 2006-06-29 2012-08-03 Rhodia Recherches & Tech Procede de preparation d'hydroquinone purifiee
FR2925489B1 (fr) * 2007-12-19 2010-02-05 Rhodia Operations Procede de preparation de pyrocatechol purifie
US8530705B2 (en) 2009-03-25 2013-09-10 Sumitomo Chemical Company, Limited Purification method of dihydroxybenzene
CN110902919A (zh) * 2019-11-27 2020-03-24 怀化旺达生物科技有限公司 一种氨基硫脲生产废水处理方法
CN116969815B (zh) * 2023-09-25 2023-11-24 山东富宇石化有限公司 一种对苯二酚纯化和脱水方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3968171A (en) * 1970-03-05 1976-07-06 The Goodyear Tire & Rubber Company Process for the continuous isolation of dihydric phenols
US3927124A (en) * 1970-03-05 1975-12-16 Goodyear Tire & Rubber Process for the neutralization of alkyl aromatic hydroperoxide rearrangement reaction products
JPS501011B1 (enrdf_load_stackoverflow) * 1970-06-18 1975-01-14
US3884983A (en) * 1970-08-19 1975-05-20 Goodyear Tire & Rubber Process for the production of photograde hydroquinone
US3895079A (en) * 1972-06-28 1975-07-15 Goodyear Tire & Rubber Process for recovery of dihydric phenols
JPS4943933A (enrdf_load_stackoverflow) * 1972-09-04 1974-04-25
JPS5136430A (en) * 1974-09-20 1976-03-27 Mitsui Petrochemical Ind Hidorokinon no seiseihoho

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Publication number Publication date
EP0001043A3 (en) 1979-04-04
DE2861158D1 (en) 1981-12-24
JPS6118537B2 (enrdf_load_stackoverflow) 1986-05-13
BR7805951A (pt) 1979-05-02
US4119791A (en) 1978-10-10
EP0001043A2 (en) 1979-03-21
CA1103277A (en) 1981-06-16
JPS5452041A (en) 1979-04-24

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